1. Field of the Invention
The invention relates to a portable power wrench with a manually operated power control means. In particular, the invention concerns an angle type power wrench having an elongate housing with a handle and a power control means in the form of a trigger located at its rear end and an angle drive head with an output shaft at its forward end.
2. Description of the Related Art
There is a well known problem to handle an angle power wrench of the above type during an initial assembly sequence wherein one or more parts to be secured by a screw joint have to be put in their correct positions at the same time as the power wrench should be properly connected to the screw joint for applying a rotational movement thereon during an initial running down phase. When starting an assembly operation with a prior art power wrench the operator has to put the parts to be assembled in correct positions by one hand while supporting the power wrench via the handle at the rear end of the housing by the other hand. Supporting the power wrench via the rear end handle is necessary to be able to press the power control trigger and start the wrench. This means that the operator has to support the weight and balance the power wrench by one hand while holding the parts to be assembled and the screw joint by the other hand. By supporting the power wrench by the rear end handle only it is difficult for the operator to accurately balance and guide the power wrench with a nut socket attached to the output shaft into engagement with the screw joint. In practice, operators perform this “point and aim” phase by grabbing the housing at the angle drive head and at the same time holding the screw joint parts in correct positions by one hand, while he supports the rear end of the wrench and activates the power control trigger by his other hand. This two-hand power wrench guiding is a very tricky exercise and calls for a lot of experience together with a certain hand size to be able to grab and guide the housing at the angle drive head and the parts being assembled at the same time.